Heating
Heating System Installation
A heating system should disappear into the background of your life for 15–20 years. Whether that happens is decided at installation: correct sizing (an oversized furnace short-cycles and wears out early), proper venting, gas line adequacy, and combustion setup. The efficiency rating on the box only materializes when the install is right.
Heating System Installation: at a glance
- What it is:
- Full installation of a new heating system — gas or oil furnace, or boiler — including sizing, venting, gas or fuel connections, and commissioning.
- When you need it:
- When the old furnace or boiler is past 15–20 years, needs a cracked heat exchanger replaced, or heats unevenly despite repairs.
- The key decision:
- Efficiency ratings (AFUE) matter, but proper sizing and ductwork condition matter more for comfort. Ask how the installer calculated the size and whether your ducts were evaluated.
Key facts
| Typical timeline | 1–3 days depending on system type and venting |
|---|---|
| Key risk | Skipping the duct evaluation — new furnace, same airflow problems |
| Relative scope | Large — equipment, venting, fuel connections, commissioning |
| Best for | Systems 15–20+ years old, cracked heat exchangers, chronic uneven heating |
Typical ranges for the material category — your home, climate, and installer quality move real results.
Do this first
- Know your fuel options and prices — gas, oil, propane, and electric each change the math.
- Ask whether your venting supports a high-efficiency (condensing) unit or if a mid-efficiency model fits your home better.
- Get the Manual J in writing and compare scopes across at least three bids.
- For boilers, ask specifically about the near-boiler piping — it decides system efficiency as much as the boiler itself.
What the crew does
- Perform a Manual J heat-loss calculation to size the system to your home — not to the old unit's size
- Evaluate venting: chimney condition for atmospheric units, or plan direct-vent/PVC venting for high-efficiency models
- Verify gas line capacity and upgrade where the new unit's input requires it
- Remove the old furnace or boiler and dispose of it properly
- Set the new unit, connect venting, gas, electrical, and condensate (for condensing models)
- Commission: verify temperature rise, gas pressure, combustion, and safety controls
Common questions
Neither is universally better — it depends on your home. Forced-air furnaces pair naturally with central AC and filter air; boilers deliver exceptionally comfortable, even radiant heat and last longer on average. If your home already has ductwork or radiators, staying with that distribution type is usually the practical choice.
AFUE is the percentage of fuel converted to heat — 80% vs. 96% means 16 cents more heat per dollar of fuel. Higher AFUE costs more upfront and needs different venting and condensate handling. The payback depends on your climate and fuel prices; in cold climates with expensive fuel, high efficiency usually wins.
A straightforward furnace swap is typically a day; boilers and jobs with venting or gas-line changes run two to three days. Ask for the schedule and what's included — permits, disposal, thermostat — before work starts.
Heating System Installation by state
Local climate changes the right material and details. Pick your state for heating system installation guidance tuned to local conditions.